6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-25 14:32:53 +00:00
Code Issues Projects Releases Wiki Activity
b2c79f2f63
llvm-6502/test/Transforms/InstCombine/malloc-free-delete.ll

123 lines
4.1 KiB
LLVM
Raw Normal View History

Teach instCombine to remove malloc+free if malloc's only uses are comparisons to null. Patch by Matti Niemenmaa. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104871 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-27 19:09:06 +00:00
; RUN: opt < %s -instcombine -S | FileCheck %s
testcase for PR1201 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35980 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-14 00:19:36 +00:00
; PR1201
define i32 @main(i32 %argc, i8** %argv) {
teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users. This means we can do cheap DSE for heap memory. Nothing is done if the pointer excapes or has a load. The churn in the tests is mostly due to objectsize, since we want to make sure we don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159876 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-06 23:09:25 +00:00
; CHECK: @main
manually upgrade a bunch of tests to modern syntax, and remove some that are either unreduced or only test old syntax. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133228 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-17 03:14:27 +00:00
%c_19 = alloca i8*
%malloc_206 = tail call i8* @malloc(i32 mul (i32 ptrtoint (i8* getelementptr (i8* null, i32 1) to i32), i32 10))
store i8* %malloc_206, i8** %c_19
%tmp_207 = load i8** %c_19
tail call void @free(i8* %tmp_207)
ret i32 0
teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users. This means we can do cheap DSE for heap memory. Nothing is done if the pointer excapes or has a load. The churn in the tests is mostly due to objectsize, since we want to make sure we don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159876 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-06 23:09:25 +00:00
; CHECK-NEXT: ret i32 0
testcase for PR1201 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35980 91177308-0d34-0410-b5e6-96231b3b80d8
2007-04-14 00:19:36 +00:00
}
Teach instCombine to remove malloc+free if malloc's only uses are comparisons to null. Patch by Matti Niemenmaa. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104871 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-27 19:09:06 +00:00
teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users. This means we can do cheap DSE for heap memory. Nothing is done if the pointer excapes or has a load. The churn in the tests is mostly due to objectsize, since we want to make sure we don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159876 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-06 23:09:25 +00:00
declare noalias i8* @calloc(i32, i32) nounwind
Teach InstCombine that lifetime intrincs aren't a real user on the result of a malloc call. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136732 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-02 22:08:01 +00:00
declare noalias i8* @malloc(i32)
Teach instCombine to remove malloc+free if malloc's only uses are comparisons to null. Patch by Matti Niemenmaa. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104871 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-27 19:09:06 +00:00
declare void @free(i8*)
define i1 @foo() {
; CHECK: @foo
; CHECK-NEXT: ret i1 false
%m = call i8* @malloc(i32 1)
%z = icmp eq i8* %m, null
call void @free(i8* %m)
ret i1 %z
}
Teach InstCombine that lifetime intrincs aren't a real user on the result of a malloc call. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136732 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-02 22:08:01 +00:00
declare void @llvm.lifetime.start(i64, i8*)
declare void @llvm.lifetime.end(i64, i8*)
teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users. This means we can do cheap DSE for heap memory. Nothing is done if the pointer excapes or has a load. The churn in the tests is mostly due to objectsize, since we want to make sure we don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159876 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-06 23:09:25 +00:00
declare i64 @llvm.objectsize.i64(i8*, i1)
declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
declare void @llvm.memmove.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i32, i1) nounwind
Teach InstCombine that lifetime intrincs aren't a real user on the result of a malloc call. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136732 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-02 22:08:01 +00:00
teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users. This means we can do cheap DSE for heap memory. Nothing is done if the pointer excapes or has a load. The churn in the tests is mostly due to objectsize, since we want to make sure we don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159876 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-06 23:09:25 +00:00
define void @test3(i8* %src) {
Teach InstCombine that lifetime intrincs aren't a real user on the result of a malloc call. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136732 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-02 22:08:01 +00:00
; CHECK: @test3
; CHECK-NEXT: ret void
%a = call noalias i8* @malloc(i32 10)
call void @llvm.lifetime.start(i64 10, i8* %a)
call void @llvm.lifetime.end(i64 10, i8* %a)
teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users. This means we can do cheap DSE for heap memory. Nothing is done if the pointer excapes or has a load. The churn in the tests is mostly due to objectsize, since we want to make sure we don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159876 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-06 23:09:25 +00:00
%size = call i64 @llvm.objectsize.i64(i8* %a, i1 true)
store i8 42, i8* %a
call void @llvm.memcpy.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i32 1, i1 false)
call void @llvm.memmove.p0i8.p0i8.i32(i8* %a, i8* %src, i32 32, i32 1, i1 false)
call void @llvm.memset.p0i8.i32(i8* %a, i8 5, i32 32, i32 1, i1 false)
%alloc2 = call noalias i8* @calloc(i32 5, i32 7) nounwind
%z = icmp ne i8* %alloc2, null
Teach InstCombine that lifetime intrincs aren't a real user on the result of a malloc call. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136732 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-02 22:08:01 +00:00
ret void
}
Fix logical error when detecting lifetime intrinsics. Don't replace a gep/bitcast with 'undef' because that will form a "free(undef)" which in turn means "unreachable". What we wanted was a no-op. Instead, analyze the whole tree and look for all the instructions we need to delete first, then delete them second, not relying on the use_list to stay consistent. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136752 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-03 00:43:35 +00:00
;; This used to crash.
define void @test4() {
; CHECK: @test4
; CHECK-NEXT: ret void
%A = call i8* @malloc(i32 16000)
%B = bitcast i8* %A to double*
%C = bitcast double* %B to i8*
call void @free(i8* %C)
ret void
}
teach instcombine to remove allocated buffers even if there are stores, memcpy/memmove/memset, and objectsize users. This means we can do cheap DSE for heap memory. Nothing is done if the pointer excapes or has a load. The churn in the tests is mostly due to objectsize, since we want to make sure we don't delete the malloc call before evaluating the objectsize (otherwise it becomes -1/0) git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159876 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-06 23:09:25 +00:00
; CHECK: @test5
define void @test5(i8* %ptr, i8** %esc) {
; CHECK-NEXT: call i8* @malloc
; CHECK-NEXT: call i8* @malloc
; CHECK-NEXT: call i8* @malloc
; CHECK-NEXT: call i8* @malloc
; CHECK-NEXT: call i8* @malloc
; CHECK-NEXT: call i8* @malloc
; CHECK-NEXT: call i8* @malloc
; CHECK-NEXT: call void @llvm.memcpy
; CHECK-NEXT: call void @llvm.memmove
; CHECK-NEXT: store
; CHECK-NEXT: call void @llvm.memcpy
; CHECK-NEXT: call void @llvm.memmove
; CHECK-NEXT: call void @llvm.memset
; CHECK-NEXT: store volatile
; CHECK-NEXT: ret
%a = call i8* @malloc(i32 700)
%b = call i8* @malloc(i32 700)
%c = call i8* @malloc(i32 700)
%d = call i8* @malloc(i32 700)
%e = call i8* @malloc(i32 700)
%f = call i8* @malloc(i32 700)
%g = call i8* @malloc(i32 700)
call void @llvm.memcpy.p0i8.p0i8.i32(i8* %ptr, i8* %a, i32 32, i32 1, i1 false)
call void @llvm.memmove.p0i8.p0i8.i32(i8* %ptr, i8* %b, i32 32, i32 1, i1 false)
store i8* %c, i8** %esc
call void @llvm.memcpy.p0i8.p0i8.i32(i8* %d, i8* %ptr, i32 32, i32 1, i1 true)
call void @llvm.memmove.p0i8.p0i8.i32(i8* %e, i8* %ptr, i32 32, i32 1, i1 true)
call void @llvm.memset.p0i8.i32(i8* %f, i8 5, i32 32, i32 1, i1 true)
store volatile i8 4, i8* %g
ret void
}
When code size is the priority (Oz, MinSize attribute), help llvm turning a code like this: if (foo) free(foo) into that: free(foo) Move a call to free from basic block FB into FB's predecessor, P, when the path from P to FB is taken only if the argument of free is not equal to NULL. Some restrictions apply on P and FB to be sure that this code motion is profitable. Namely: 1. FB must have only one predecessor P. 2. FB must contain only the call to free plus an unconditional branch to S. 3. P's successors are FB and S. Because of 1., we will not increase the code size when moving the call to free from FB to P. Because of 2., FB will be empty after the move. Because of 2. and 3., P's branch instruction becomes useless, so as FB (simplifycfg will do the job). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171762 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 18:37:41 +00:00
;; When a basic block contains only a call to free and this block is accessed
;; through a test of the argument of free against null, move the call in the
;; predecessor block.
;; Using simplifycfg will remove the empty basic block and the branch operation
;; Then, performing a dead elimination will remove the comparison.
;; This is what happens with -O1 and upper.
; CHECK: @test6
define void @test6(i8* %foo) minsize {
; CHECK: %tobool = icmp eq i8* %foo, null
;; Call to free moved
; CHECK-NEXT: tail call void @free(i8* %foo)
; CHECK-NEXT: br i1 %tobool, label %if.end, label %if.then
; CHECK: if.then:
;; Block is now empty and may be simplified by simplifycfg
; CHECK-NEXT: br label %if.end
; CHECK: if.end:
; CHECK-NEXT: ret void
entry:
%tobool = icmp eq i8* %foo, null
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
tail call void @free(i8* %foo)
br label %if.end
if.end: ; preds = %entry, %if.then
ret void
}
Reference in New Issue Copy Permalink